The FBI has uncovered what officials consider a serious plot by jihadists to bomb the Holland Tunnel in hopes of causing a torrent of water to deluge lower Manhattan, the Daily News has learned.

The terrorists sought to drown the Financial District as New Orleans was by Hurricane Katrina, sources said. They also wanted to attack subways and other tunnels.

Counterterrorism officials are alarmed by the “lone wolf” terror plot because they allegedly got a pledge of financial and tactical support from Jordanian associates of top terrorist Abu Musab al-Zarqawi before he was killed in Iraq, a counterterrorism source told The News.

It’s not clear, however, if any cash or assistance was delivered.

The News has learned that at the request of U.S. officials, authorities in Beirut arrested one of the alleged conspirators, identified as Amir Andalousli, in recent months. Agents were scrambling yesterday to try to nab other suspects, sources said.

DHS and the FBI released a statement in response to the story today, confirming that it had disrupted an attack that was in the “planning stages.” Subsequent reportage has noted that this plot was largely hatched on internet chat rooms, and was far from operational. The AP quotes Rep. Peter King noting that “there was nothing imminent [about the plot], but it was being monitored for long period of time.” And a second Daily News story highlights the absurdity of the idea that an attack on the Holland Tunnel would flood the financial district of Manhattan.